Q Are there any reputable studies showing that turmeric is more bioavailable than curcumin?

SAXON, Toledo, OH

A Not per se. Curcuma longa (turmeric) has long been used in Ayurvedic medicine, principally as a treatment for inflammatory conditions. Turmeric’s primary constituents include the three curcuminoids—curcumin, demethoxycurcumin, and bisdemethoxycurcumin—as well as volatile oils (tumerone, atlantone, and zingiberone), resins, sugars, and proteins. The most celebrated constituent is curcumin, which comprises 2–8% of turmeric, and is typically extracted from turmeric, to its potency’s detriment. However, altogether there are at least 10 bioactive components found in turmeric, which produce a wide array of biomedical benefits. Curcumin’s activity is the most touted, especially for its anti-inflammatory effect, especially for those effects on cancer.

Research has shown curcumin to be a highly pleiotropic (possessing multiple effects) molecule. Accordingly, it is capable of interacting with a great many molecular targets involved in inflammation. But the repeated problem, as “authoritatively” presented, is low bioavailability.

Branching out from early cell culture and animal research, clinical trials have found curcumin to possess powerful therapeutic agencies in diseases such as inflammatory bowel disease, arthritis, pancreatitis, and chronic anterior uveitis, not to mention certain types of cancer. It may well be true that curcumin’s rapid plasma clearance and conjugation renders its therapeutic use less than desirable, leading researchers to investigate the benefits of complexing curcumin with other substances to increase systemic bioavailability.

While clinical trials have provided a deeper understanding of the mechanisms and therapeutic potential of curcumin, overhanging the published research is the specter of “low bioavailabilty.” Could this notion be a chimeric fantasy, fostered by those looking for a new profit avenue?

It is interesting to note that one of the leading “enhanced bioavailability” curcumin formulations makes significant use of the essential oils that are removed by the extraction process. Could turmeric contain its own delivery system? As we have previously reported, when you cut a piece of fresh turmeric, you will notice that your hands turn yellow, an indication that there is good bioavailability, because skin has evolved to be highly resistant to penetration by foreign substances. Also, if you’re taking whole turmeric, your stool does not turn yellow. Turmeric, containing curcumin, is certainly quite bioavailable. (See
page 21 in this issue for Durk & Sandy’s take on turmeric, an extraordinary nutrient.)